Playing in rural Alabama, defensive tackle Tyler Nero of Atmore Escambia County didn't have many chances to showcase his skills on a big stage. When the opportunity finally arose, he made the most of it.

"The thing that really struck me was how strong Nero was," Rivals.com Southeast Analyst Keith Niebuhr said. "He's also very quick and explosive off the ball. Nero plays with an excellent pad level, which allows him to get tremendous leverage versus centers and guards. He has a powerful set of legs that never stop moving. He drives hard into the opposition and sometimes knocks his man completely out of the play. Nero is very good at taking on the double team."

After a solid senior season, Nero is now a four-star prospect.

He is one of 13 prospects being moved from three to four stars who fell outside the Rivals250.

Leamon, a Clemson commit who is 6-6, 295 pounds, impressed at the Offense-Defense Bowl.

"Leamon has the prototypical long and lean frame of a left tackle but he proved to be more than just a big body at the Offense-Defense Bowl," Rivals.com Southwest Analyst Brian Perroni said. "He moves his feet well for a big kid and has the potential to be very good."

Lawson also is headed to Clemson.

"To be honest, Lawson was not one of the main guys on my radar coming into the Offense-Defense week but it was hard to ignore what he did in practice," Perroni said. "He has a very quick first step and does a great job pursuing the play from the backside.

Summers, an N.C. State commit, and Towles, who will play for Kentucky, displayed all the skills to receive the bump, according to national analyst Mike Farrell.

"James Summers impressed me more on film during his amazing playoff run than at the Shrine Bowl, but even at the Shrine Bowl you could see he has a live arm and he can move around," Farrell said. "But it was truly his playoff film where he dominated two of the top teams in the state loaded with D-I talent that led to his boost to four-star status. He was a one-man show."

Of Towles, Farrell said, "He's a guy with a strong arm, he's very accurate, he can move around for a big kid, he's got great poise, and he's a winner. Everything about him looks like a potential SEC quarterback and possible NFL quarterback, when you combine all of his attributes together."

"Lewis started off his senior year strong, but injuries slowed him down as the season progressed," Midway Analyst Josh Helmholdt said. "He was fully healthy again when he showed up for the Offense-Defense Bowl in Dallas last month, and was one of the most effective playmakers in that game. Lewis is a sure-handed receiver, but he is also explosive and adept at picking up yards after the catch."

Greene, an Alabama commit, and Jelks, who is headed to Vanderbilt, are two physically impressive players who each proved bump worthy.

"The thing you really like about both of these kids is their frames," Niebuhr said. "These guys are built like your prototypical SEC tackle. But it's more than that. Both also are incredibly athletic for players their size and can get to that second level in a flash. The upside for both is extremely high."

Echols, who is committed to Texas, looked sharp at the Under Armour All-America Game. Murray, another future Buckeye, is coming off an excellent senior season.

"We had a chance to see Murray's senior film since our last rankings update, and it necessitated a bump to four stars," Helmholdt said. "Playing safety for Steubenville, Murray devastates receivers who try to catch the ball over the middle of the field. It is difficult to convey the violence with which he plays the game."

Moore also stood out last fall.

"Moore was one of the best players I saw all weekend at the Louisiana state championships and there was a ton of talent there," Perroni said. "He is electric with the ball in his hands and could make a dangerous wide receiver."

Finally, there's Kallon, the Georgia Tech commit who didn't begin playing football until 2011 after having been raised in England. The 6-5, 260-pound strongside end with the size 16 shoe showed enormous promise, according to Niebuhr.

"This kid has an NFL body right now," Niebuhr said. "He's huge, and he's still growing. While he is still raw and can play a bit high at times, watch Kallon's film and you will be impressed. He's already an excellent pass-rusher who has great quickness, strength and determination. And quite frankly, he's freakishly athletic. What he has been able to accomplish in such a short period of time is truly remarkable. As he continues to better understand the game, he should develop into an all-conference type of player."